AbstractsComputer Science

The penetration of distributed generation (DG) in electrical distribution systems has been consistently increasing due to its great potential to improve system performance in terms of reliability, power quality and loss reduction. However, achieving these benefits is not trivial given the diverse issues resulting from distributed generation integration. One of them is the islanded operation of DGs since such operation generates hazards for human safety and compromises electrical network quality and infrastructure. It is thus current practice, according to DG Interconnection Guidelines to disconnect all DGs upon unintentional islanding detection. This thesis proposes the use of Intelligent Relay (IR) as a passive device for islanding detection of synchronous DGs and outlines the setting methodology. The intelligent relay employs multi-variate analysis and data mining techniques to extract the patterns of islanded synchronous DGs from time-domain features obtained from off-line simulation of typical islanding events. The captured islanding signature for any DG is represented in the form of a Decision Tree (DT) which determines the tripping logic, protection handles and thresholds of the Intelligent Relay.A distribution feeder with multiple DGs connected is modeled in Simulink as a benchmark system for Intelligent Relay testing. The performance of the IR is quantified in terms of Dependability and Security indices and is compared to the performance of conventional passive protective relays. In order to simulate realistic situations, a variety of operating conditions is configured and operating condition-dependent dedicated IR settings are obtained. The validity and applicability of the obtained IR settings are examined for an unknown set of islanding and non-islanding events including the ones originating from symmetrical, asymmetrical and arcing shunt faults. Last, but not least, a method is proposed to use the high-performance dedicated relay settings in an adaptive fashion in order to accommodate a range of similar operating conditions, thus avoiding repetitive IR training. The IR was found to exhibit consistently superior overall performance to all considered currently used passive protective devices. It also features a much smaller Non-Detection-Zone by virtue of its superior performance for islanding conditions where the load and the formed island generation are nearly balanced. La pénétration de la production décentralisée (DG) dans les réseaux de distribution électrique est en croissance constante grâce au grand potentiel pour améliorer les performances du système en termes de fiabilité, de qualité de l'onde et la réduction des pertes. Cependant, la réalisation de ces avantages n'est pas évident étant donné les diverses questions découlant de l'intégration de la production décentralisée. Un des problèmes est l'opération du DG pendant d'îlotage de la centrale. Cette opération génère des risques pour la sécurité humaine et compromet la qualité du réseau électrique et de l'infrastructure. Il est donc pratique…